This invention relates to an internal combustion piston engine, the cylinder of which has a main combustion chamber, in which the combustion is initiated, and at least one secondary combustion chamber which is connected at least temporarily to the main combustion chamber via one or more channels.
Internal combustion piston engines with subdivided combustion chambers are known. Moreover, it is not novel that the combustion process can be influenced by this sub-division. Recently, an internal combustion engine of this type has been described, for example, in German Offenlegungsschrift 27 45 902. In the embodiment according to FIG. 4 of this printed publication, the main combustion chamber and the secondary combustion chamber are continuously connected to one another. Thus, approximately the same pressure prevails in the two chambers at the end of a compression stroke. The combustion process in the main combustion chamber can therefore be influenced only by moving pressure waves which are said to pass from the secondary combustion chamber into the main combustion chamber after the mixture has been ignited. In addition, heating of the thin, disc-shaped cap of the piston also plays a role in promoting combustion. It must be doubted whether it is possible substantially to improve the combustion and to reduce the emission of pollutants by means of the pressure waves which run at high velocity and only for a short time.